Method for heating articles having complicated forms

ABSTRACT

Method for heating an article having a part of complicated form by a tracing pipe which comprises causing heat to conduct through the medium of metal piece fixed between said article and said tracing pipe.

United States Patent Inventor Masao Ando Kanagawaken, Japan Appl. No.790,329 "Filed Jan. 10, 1969 Patented Jan. 5,1971 Assignee ChissoCorporation Osaka, Japan an organization of Japan Priority Jan. 31, 1968Japan No. 43/5924 METHOD FOR HEATING ARTICLES HAVING COMPLICATED FORMS 2Claims, 2 Drawing Figs.

US. Cl

[51] lnt.Cl F28d 7/02 [50] Field ofSearch 165/1, 164, 172, 171, 186

[56] References Cited UNITED STATES PATENTS 3,331,946 7/1967 Bilbro165/164 FORElGN PATENTS 1,445,883 6/1966 France 165/164 PrimaryExaminer-Charles Sukalo Attorney- Fred C. Philpitt ABSTRACT: Method forheating an article having a part of complicated form by a tracing pipewhich comprises causing heat to conduct through the medium of metalpiece fixed between said article and said tracing pipe.

METHOD FOR HEATING ARTICLES HAVING COMPLICATED FORMS This inventionrelates to a method for heating an article having a part of complicatedform and more particularly to a method for heating an article having apart of complicated form such as a pipe line equipped with a part ofcomplicated form such as valves, flanges, pumps, etc. a storage vessel,a reactor, etc. by the use of a tracing pipe (an embracing pipe) heatedby electric heat, fluid such as steam, heating oil, etc. which ischaracterized in causing heat to conduct through the medium of metalpiece between the material to be heated and the tracing pipe for heatingpurpose.

It is a common practice to transport aliquid having a high viscositysuch as fuel heavy oil through a pipe line by heating said liquid to atemperature which gives a sufficient low viscosity.

In order to prevent the reduction. of liquid temperature in such a case,the pipe line is insulated and in case of a long distance pipe line,beside the insulation, a tracing pipe in which fluid such as steam,heating oil or the like, as a heating source, is passing or a tracingpipe which utilizes electric heat, is used. I

As a tracing pipe, a steel pipe such as a gas pipe is used from theeconomical reason, but it has high rigidity and inferior processability.Accordingly, in complicated parts such as flange parts, valves, it isdifficult to bring the parts to be heated close enough to the tracingpipe by which mutual heat conduction is prevented and heating andtemperature maintenance become difficult.

In order to overcome such a drawback and enhance heat conduction, it hasbeen commonly carried out to fill a certain kind of heat-conductingcement between the gap formed between them.

However, such a heat-conducting cement has drawbacks in the points thatits heat conductivity is relatively so low that it is in an extent ofKcaL/m hr. C. and'its cost is expensive.

An object of the present invention is to provide a method whichovercomes the above-mentioned drawback of the conventional method.

The above-mentioned object of the present invention can be attained bythe method of the present invention which is characterized in causingheat to conduct by the medium of metal piece fixed between to be heatedmaterial and a tracing pipe in case of to be heated materials having apart of a complicated form.

The method of the present invention can be more fully understood byreferring to the accompanied drawings.

Both FIG. 1 and FIG. 2 are schematic view ofa pipe line in which theheating method of the present invention is applied.

In FIG. 1, l is a pipe to be heated and whose temperature is maintainedby a tracing pipe 4. In the drawing, insulating layers are omitted. 2 isa flange and 3 is a valve. On account of irregular forms of the pipeline at these parts, the close placement or contact of the pipe 1 andthe valve 3 to the tracing pipe 4 is difficult, and the mutual heatconduction between the pipe I and the valve 3 and the tracing pipe 4 isprevented. In case where the pipe 1 and the tracing pipe 4 are steelpipes, steel plates 8 of similar material are welded as indicated by 9to the pipe 1 at the part ofthe flange 2 and the thickness of the steelplate 8 is determined so as to conduct heat from the tracing pipe 4 tothe pipe I mainly through the steel plate 8. Since the thermalconductivity ofsteel plate is about 50 KcaL/m hr. C., it is higher thanthat of a heat-conducting cement, less expensive and of highermechanical strength. When the contact of the tracing pipe 4 and thesteel plate 8 is not sufficient, it is possible to use a small amount ofa heat-conducting cement at this part.

With regard to the heat conduction between the valve 3 and the tracingpipe 4, since the valve 3 is mostly of casted material to whichapplication of welding is difficult and which has the danger ofdeformation and damage, steel plate 5 ofsimilar material is welded asindicated by 6 to the tracing pipe 4 when the tracing pipe 4 is made ofsteel and the thickness of the steel plate 5 is determined in such a waythat the heat conduction between the valve 3 and the tracing pipe 4 iscarried out mainly through the steel plate 5 Since the valve 3 hasgenerally a complicated surface, the part of the steel plate 5 and thevalve 3 which are located at mutually close positions. should bemachined so as to give as narrow gaps as possible. It is often effectiveto use a small amount of heat-conducting cement 7 in such gaps.

11 is a mean such as an U-shapcd bolt which is used to fix the tracingpipe 4 to the steel plate 8 and has no direct connection to the presentinvention.

In case where two pipes are connected by flanges, they take forms suchas that indicated in FIG. 2, but this case can be considered to be theone of FIG. I from which the valve 3, the tracing pipe 4, the steelplate 5, the welded part 6 which connects these parts and theheat-conducting cement 7 used in the gap between the valve 3 and thesteel plate 5, are removed. Accordingly, the explanation will be thesame as in the case of FIG. 1 if the explanation as to theabove-mentioned parts is omitted.

Further since the steel plates 5 or 8 has the object of con ducting heatfrom the tracing pipe 4 to the valve 3 or the pipe 1, it is possible orrather preferable to use a metal other than steel which has betterconductivity. As for the fitting method of the tracing pipe 4 and thevalve 3 or the pipe 1, various suitable method can be applied accordingto the parts.

The foregoing explanation is directed to valve flange parts in a pipeline, but with regard to a pump, a metering instrument such as a flowmeter or the like, a storage vessel, a reactor, etc., the sameapplication can be carried out.

According to the method ofthe present invention, even in a pipe lineequipped with a valve, flanges,- pumps, etc, a complicated part such asa storage vessel, a reactor, etc., the object of economical heatingwithout subjecting a tracing pipe to complicated working or using alarge quantity of expensive heat-conducting cement can be attained. Theadvantage ohtained by the method of the present invention in variousfield ofindustry will be enormous.

Iclaim:

1. In the known method of heating a pipeline by disposing a tracing pipeheat source adjacent to said pipeline, the improvement which comprises,making the heat transfer more efficient at a pipeline location ofcomplicated form by:

a. disposing a metal plate adjacent to the portion of the pipeline thathas a complicated form;

b. welding one side of said metal plate to said tracing pipe;

and

c. connecting the other side of said metal plate to said area of thepipeline that is of complicated form by filling the space therebetweenwith heat conducting cement, said other side of said metal plate havinga shape that generally corresponds to the shape of the pipeline at saidlocation of complicated form.

2. In the known method of heating a pipeline by disposing a tracing pipeheat source adjacent to said pipeline, the improvement which comprises,making the heat transfer more effieient at a pipeline location ofcomplicated form by:

a. disposing a metal plate adjacent to the portion of the pipeline thathas a complicated form;

b. welding one side of said metal plate to said pipeline adjacent saidlocation of complicated shape; and

c. connecting the other side of said metal plate to the tracing pipe byfilling the space therebetween with heat conducting cement.

1. In the known method of heating a pipeline by disposing a tracing pipeheat source adjacent to said pipeline, the improvement which comprises,making the heat transfer more efficient at a pipeline location ofcomplicated form by: a. disposing a metal plate adjacent to the portionof the pipeline that has a complicated form; b. welding one side of saidmetal plate to said tracing pipe; and c. connecting the other side ofsaid metal plate to said area of the pipeline that is of complicatedform by filling the space therebetween with heat conducting cement, saidother side of said metal plate having a shape that generally correspondsto the shape of the pipeline at said location of complicated form.
 2. Inthe known method of heating a pipeline by disposing a tracing pipe heatsource adjacent to said pipeline, the improvement which comprises,making the heat transfer more efficient at a pipeline location ofcomplicated form by: A. disposing a metal plate adjacent to the portionof the pipeline that has a complicated form; b. welding one side of saidmetal plate to said pipeline adjacent said location of complicatedshape; and c. connecting the other side of said metal plate to thetracing pipe by filling the space therebetween with heat conductingcement.